Cutting tool compensator for rotary machine tool

Abstract

A machine tool of the type having a rotatably mounted housing circumscribing a longitudinal axis of rotation and adapted for having coupled thereto a tool holder having at least one cutting tool which is adjustable radially of the axis such that a cutting edge of the cutting tool is caused to engage and disengage a workpiece as a result of a camming action between the cutting tool and a drawbar resulting from reciprocation of the drawbar as the roller screw to which it is attached rotates.

We claim: 
     
       1. An integral machine tool of the type circumscribing a longitudinal axis of rotation and adapted for having coupled thereto a tool holder which rotates about said axis and includes at least one cutting tool which is adjustable radially of said axis, said machine tool comprising: a non-rotatable spindle body having a cavity therein extending along said axis from a first end to a second end;   a rotatable spindle shaft extending through said cavity and having an opening therethrough extending along said axis from one end to the other, said one end adapted to be coupled to said tool holder;   means coupled to said rotatable spindle shaft for rotating said rotatable spindle shaft;   a roller screw mounted within said opening, said roller screw including a leadscrew spindle extending along said axis and at least one nut body operatively coupled thereto, said roller screw being so mounted that rotary motion of said leadscrew spindle about said axis causes movement of said at least one nut body along said axis;   means coupled to said leadscrew spindle for controllably rotating said leadscrew spindle, said means including a non-rotating housing coupled to said means coupled to said rotatable spindle shaft;   means including a drawbar which is reciprocatingly and rotatably mounted with said opening and extends along said axis, said drawbar means being adapted to be coupled to said tool holder for rotation therein when said tool holder is rotated and for causing radial movement of said cutting tool when said drawbar means is reciprocated; and,   means positioned within said opening and coupled to said drawbar means and to said at least one nut body for reciprocating said drawbar means along said axis in response to movement of said at least one nut body along said axis, said reciprocating means being non-rotatable.   
     
     
       2. The machine tool of claim 1 wherein said reciprocating means includes a slide member extending along said axis and having a first open end and an axially spaced second open end and wherein one end of said drawbar extends into said first open end and includes means coupled thereto for preventing axial movement of said drawbar relative to said slide member but permitting said drawbar to rotate relative to said slide member. 
     
     
       3. The machine tool of claim 2 wherein a portion of said leadscrew spindle extends into said second open end of said slide member, and said at least one nut body is operatively coupled to said portion and attached to said slide member to prevent movement of said at least one nut body relative to said slide member. 
     
     
       4. The machine tool of claim 2 wherein said leadscrew spindle rotating means is a motor, and further including means for coupling a portion of said leadscrew spindle extending out of said second open end of said slide member to said motor. 
     
     
       5. The machine tool of claim 4 wherein said coupling means includes a drive shaft which extends within said spindle shaft, one end of said drive shaft being coupled to said motor and the other end of said drive shaft being coupled to said leadscrew spindle. 
     
     
       6. The machine tool of claim 5 further including a stationary sleeve positioned with said spindle shaft and keyed to said slide member, and wherein said drive shaft extends through said sleeve by means of an opening extending from one sleeve end to an opposing sleeve end. 
     
     
       7. The apparatus of claim 4 wherein said motor is a stepper motor. 
     
     
       8. The apparatus of claim 7 wherein said motor is coupled to a controller mechanism. 
     
     
       9. The machine tool of claim 1 including a tool holder which is coupled to said one end of said rotatable spindle shaft and which is coupled to said drawbar means, said tool holder having coupled thereto a cutting tool for cutting a workpiece during rotation of said rotatable spindle shaft about said axis, said cutting tool being caused to move in a radial direction relative to said axis such that a cutting edge of said cutting tool is caused to engage and disengage said workpiece as a result of a camming action between said cutting tool and said drawbar means as said drawbar means is caused to reciprocate along said axis. 
     
     
       10. The apparatus of claim 9 wherein said leadscrew spindle rotating means is a motor. 
     
     
       11. The apparatus of claim 10 wherein said motor is a stepper motor. 
     
     
       12. The apparatus of claim 8 wherein an encoder is coupled to said controller mechanism and said motor. 
     
     
       13. The apparatus of claim 11 wherein said motor is coupled to a controller mechanism. 
     
     
       14. The apparatus of claim 13 wherein an encoder is coupled to said controller mechanism and said motor. 
     
     
       15. An integral machine tool of the type circumscribing a longitudinal axis of rotation and adapted for having coupled thereto a tool holder which rotates about said axis and includes at least one cuting tool which is adjustable radially of said axis, said machine tool comprising: a non-rotatable spindle body having a cavity therein extending along said axis from a first end to a second end;   a rotatable spindle shaft extending through said cavity and having a first and second end, said first end adapted to be coupled to said tool holder;   means coupled to said second end of said rotatable spindle shaft for rotating said rotatable spindle shaft, said rotating means including a housing extending away from said second end and having an opening therethrough extending along said axis from one end of said housing to the other;   a roller screw mounted within said opening, said roller screw including a leadscew spindle extending along said axis and at least one nut body operatively coupled thereto, said roller screw being so mounted that rotary motion of said leadscrew spindle about said axis causes movement of said at least one nut body along said axis;   means coupled to said leadscrew spindle for controllably rotating said leadscrew spindle, said means including a non-rotating housing coupled to said means coupled to said rotatable spindle shaft;   means including a drawbar which is reciprocatingly and rotatably mounted within said rotatable spindle shaft and extends along said axis, said drawbar means being adapted to be coupled to said tool holder for rotation therewith when said tool holder is rotated and for causing radial movement of said cutting tool when said drawbar means is reciprocated; and,   means positioned within said opening and coupled to said drawbar means and to said at least one nut body for reciprocating said drawbar means along said axis in reponse to movement of said at least one nut body along said axis.